Title:
WIRE ROD FOR ULTRA-HIGH STRENGTH SPRING, STEEL WIRE AND MANUFACTURING METHOD THEREOF
Document Type and Number:
WIPO Patent Application WO/2021/125471
Kind Code:
A1
Abstract:
The present specification relates to a wire rod for an ultra-high strength spring, a steel wire and a manufacturing method thereof and, more specifically, to a wire rod, for an ultra-high strength spring, having excellent processability, a steel wire and a manufacturing method thereof. According to an embodiment, a wire rod for an ultra-high strength spring comprises, by weight %, 0.55 to 0.65% of C, 0.5 to 0.9% of Si, 0.3 to 0.8% of Mn, 0.3 to 0.6% of Cr, 0.015% or less of P, 0.01% or less of S, 0.01% or less of Al, 0.005% or less of N, from greater than 0% to 0.04% or less of Nb, and the remainder being Fe and unavoidable impurities, and the value of formula (1) below can be from 0.77 to 0.83. (1) C + 1/6*Mn + 1/5*Cr + 1/24*Si
In formula (1) above, C, Mn, Cr and Si represent the content (weight %) of the respective elements.
Inventors:
LEE JUN MO (KR)
CHOI SEOK-HWAN (KR)
KIM HAN HWI (KR)
CHOI MYUNG SOO (KR)
CHOI SEOK-HWAN (KR)
KIM HAN HWI (KR)
CHOI MYUNG SOO (KR)
Application Number:
PCT/KR2020/008091
Publication Date:
June 24, 2021
Filing Date:
June 22, 2020
Export Citation:
Assignee:
POSCO (KR)
International Classes:
C22C38/26; B21B1/16; B21B3/00; C21D8/06
Foreign References:
| JP2019178405A | 2019-10-17 | |||
| JP6447799B1 | 2019-01-09 | |||
| KR20100131403A | 2010-12-15 | |||
| KR20150089846A | 2015-08-05 | |||
| US20140193288A1 | 2014-07-10 |
Other References:
See also references of EP 4063531A4
Attorney, Agent or Firm:
SELIM INTELLECTUAL PROPERTY LAW FIRM (KR)
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